In conventional production of lead-acid battery plates or electrodes, a grid structure is provided, and coated with a paste of powdered lead and a mixture of various lead oxides, known as leady oxide. This leady oxide is mixed with sulfuric acid to form the paste which is applied to the plates or electrodes. The pasted plates or electrodes are then cured, to harden the paste, conventionally by exposing the plates to a source of moisture and carbon dioxide, which may be performed in a humidity chamber injected with carbon dioxide gas, or, more conventionally, by exposing wet plates or electrodes to atmospheric carbon dioxide.
After curing, the plates or electrodes are formed by placing them in an electrolyte solution, such as dilute sulfuric acid, and passing a current through them. This transforms the material of the positive and negative plates into sponge lead, for a negative plate or electrode, and lead dioxide, for a positive plate.
Conventionally, forming current is provided by a commercially-available rectifying power supply, which is inherently capable of producing a substantially constant voltage, and contains circuitry for providing a substantially constant current. It is well-known that the use of a constant voltage produces poor results, due to lack of control over the current, which is the measure of forming energy, as the characteristics of the plates or electrodes change during forming. Thus, otherwise conventional rectifying power supplies are provided with circuitry to convert their output to a constant current. In view of the benefits of the instant invention, it is believed that the use of this conventional constant-current method of forming battery plates or electrodes is not efficient in terms of use of energy, since the plates or electrodes being formed change in their ability to accept forming energy during the course of the forming process. The instant invention overcomes this and other difficulties of the conventional method of forming battery plates or electrodes.